There is provided an epoxy resin composition for encapsulating a semiconductor comprising an epoxy resin (A), wherein the epoxy resin (A) including: a crystalline epoxy resin (a1) having a melting point of 50° C. to 150° C., an epoxy resin (a2) represented by formula (1), and at least one epoxy resin (a3) selected from an epoxy resin represented by formula (2) and an epoxy resin represented by a formula (3): in which R1's, which may be the same or different, represent a hydrocarbon group having 1 to 4 carbon atoms; R2's, which may be the same or different, represent a hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms; m is an integer of 0 to 5; and n is an integer of 0 to 6.